Hi all new member here, I just picked up my 16 f150 with 79k on it from the dealer last week. Day after picking it up I noticed the engine temp. needle moving ever so slightly towards the hot side then move back. Took it to the dealer service they checked it out said everything looked fine was some air in it and they took care of it and said just keep an eye on it. Was driving yesterday and seen the needle move a lot more constantly towards the hot side. I let the engine cool down and checked the coolant level and it was a little below the min mark and I couldn’t see any leaks. Plus when the truck is running the fan or blower is constantly running. Is that a sign of a coolant problem? Should I top it off and see what happens? In the meantime I’m going to contact the dealers service department and drop it off.

 

These trucks are prone to getting air pockets in the cooling system if they are not refilled (after a drain) with a vacuum system. They can be "burped" but it takes patience. The fact that the tank level was low without obvious loss of coolant just means that some of the air got purged. Keep an eye on it and it should settle down after a few more hot-cold cycles.

 

In my experience in the past with multiple 5.0 coyotes. If you're not running an oem Motorcraft thermostat they like to run warm and the fan will run more than usual. Might not be your problem may just be air in the system but it's something to check if the problem persists.

 

UPDATE: Ok so here’s a update on the situation. Didn’t drive the truck to work yesterday and let it sit all day. Took it to work this morning and the problem persisted and it was relatively cool out this morning due to it raining. Fan was on high and gauge needle moved a few times to the right a little past the half way mark. Dropped it off to the dealership service and explained to them once again what’s happening and their response was some Ford vehicles run like this and most likely there’s no problem. When I showed them the picture of the gauge they said it’s not that much over to the right. I’ve had 4 f-150s previously and the 3 out of the 4 never had this problem. The other that had this problem was my ‘13 3.5 eco boost but that would just drink the coolant for some reason. All I know is the gauge shouldn’t be moving at all and that fan shouldnt be on most of the time. it seems like to me that the dealership doesn’t want to admit or address the problem since I just purchased the truck from them. I’m going to attach the picture I showed service of the gauge and also my coolant level. I notice before startup the coolants below or right at the min mark. When it’s warmed the coolant is in the middle of the min-max mark. It’s just frustrating that I just got this truck from the dealership and I’m having this problem. Is it normal for the gauge to move to that area and then move back maybe 5-10 seconds later. Does it multiple times.

 

I’m pretty sure my gauge sits in that region you pictured like a rock on my 17 5.0.
I never see it really climb past where yours is pictured.
Try pointing the nose uphill with the engine running next time you see it elevate or when it’s at operating temp. Give the large upper hose that leads to the thermostat a few squeezes (wear thick gloves) to burp some air into the degas “overflow” reservoir and then get it topped off.. Any air you purge will continue to drop the reservoir level lower and lower.

When your gauge climbs and then drops that’s typically when your TStat opens to allow coolant to start flowing through the water neck into the crossover line that cools the heads.
You probably don’t have too much to be alarmed about but any surging in the coolant gauge is indicative of air in the system.

 

When you are monitoring the engine temperature gauge you need to keep in mind that you are not actually seeing coolant temperature. Ford now uses a Cylinder Head Temperature (CHT) sensor rather than a coolant temperature sensor. The CHT sensor sends a raw signal to the PCM which in turn interprets the signal along with other inputs and sends a mathematically created coolant temperature which is then displayed by the IPC. This system, in my experience, does change temperature much faster than a typical coolant temperature gauge would.

 

I'm not sure exactly on the requirements for the 2nd gen 5.0, but that degas bottle shouldn't be blow minimum under any circumstances, i *think* it should be there when cold, so at minimum you need to pick up a bottle of Motorcraft Yellow coolant to get the level up - that will also help with the bleeding process by elevating the coolant in the system - whilst i think you're being stiffed by the dealer (that needle shouldn't move) they can at least put the coolant level right or give you a bottle.

 

Like mentioned, you need to get some coolant and keep topping it off when you see it low like that. The problem will probably solve itself. That is a dealer I would no longer do business with period.

 

Thanks for the replies guys I appreciate it. Yeah I feel like I’m being stiffed by them as well best part is they are a FORD dealer! It’s not like there some random used car dealership. Anyway, any air in the system wouldn’t of worked it’s way out of it since I got it? Just asking lol. Plus when I took it back there the first time they said they bled the air out. I thought the level was low too and was going to top it off but decided to see what the service dept says just to be on the safe side. So it’s a waiting game now to see what they say.

 

Meh, no point waiting for them, get your 'free' gallon of yellow coolant and be done with them.

Then, if you have *any* level of DIY, go buy the funnel kit to use, it'll help bleed the system.